Method of and apparatus for controlling the cut-off of distribution valves of locomotives



Nov. 20, 1928. 1,692,620 A. W. BRUCE AL METHOD OF AND APPARAT FOR 00OLLING THE CUT-OFF DIST LOCOMOTIVES 0F RIBUTIO ALVES OF Filed April 5,1927 A TJZM Patented Nov. 20, 1928.

UNITED STATES ALFRED W. BRUCE, OF NEW YORK, N. Y., AND JOSEPH B. ENNIS,OF PATERSON, NEW

1,692,620 PATENT OFFICE.

JERSEY.

METHOD OF AND APPARATUS FOR CONTROLLING THE GUT-OFFOF DISTRIBUTIONVALVES OF LOCOMOTIVES.

Application filed Apri1 5, 1927. Serial No. 181,100.

Our invention relates to an improved apparatus for controlling thecut-off of distribution valves of locomotives, whereby 'a substantialeconomy in the use of steam is effected, and a more efiicient operationof the locomotive is ensured.

It is well known in locomotive practice that a late cutoff of thedistribution valves, that is, one occurring when the working piston hastraversed from 85 to 90% of its stroke, is desirable in starting thelocomotive; to provide the maximum power; and that when the locomotiveis running, an early cutoff, that is, one occurring when the workingpiston has traversed from 50 to 65 percent of its stroke, is necessaryin order to prevent back pressure. Some'locomotives have been equippedwith mechanisms which positively limit the movement of the valves to anearly cut-off. An objection to such mechanisms is, that when thelocomotive comes to astop, with the crank pins in certain positions, thevalves are disposed in positions where steam is entirely cut-off fromthe cylinders. To remedy this objection, auxiliary ports are provided toadmit sufficient steam to start the locomotive. It has been found,however, that such ports soon become clogged with dirt, grease, andother foreign substances, with the result that the efiiciency of thelocomotive is impaired. Other locomotives have been equipped with valvemechanisms adjustable to late cut-off position for starting, and earlycut-off position for running. Such mechanisms usually comprise a reverselever which can be movedmanually to late cut-0if position, where it islocked by a latch, which engages with a rack on a quadrant. The returnof the lever to early cut-01f position is dependent on the judgment ofthe engineer. Experience has shown that, due to negligence, the reverselever is frequently left in late cut-ofli' position after the locomotiveis start ed, with the result that a material amount of steam is wasted.7

An object of the present invention is to provide a control mechanism fordistribution'valves, which, in addition to enabling the engineer to movethe reverse lever to late cut-off position, to start the locomotive,provides for automatically returning it to early cut-off position,immediately that the engineer releases his pressure thereon.

In the accompanying drawings: Figure 1,

is a side view, in elevation, of a locomotive, havinga portion of itscab broken away to show our improved reverse lever mechanism; Fig. 2, aside view, in elevation, and on an enlarged scale, with the lowerportion broken away, of our improved reverse lever mechanism, thespringdevice being shown in vertical section on the line, a a, Fig. 4 Fig. 3,a front end view of the mechanism shown in Fig. 2; and Fig. i, atransverse section, on

a further enlarged scale, taken on the line, b E), Flg. 2, showingdetails of the latch.

Inthe practice of our invention, referring descriptively to the specificembodiment thereof which is herein exemplified as applied in alocomotive of usual type, embodying a Valschaert valve gear, which isdiagrammatically shown, and a power reverse gear of usual type, thereverse lever 10, is mounted in the cab, and has an upper arm, whichterminates in a handle, and a lower arm, to which is pivotally connectedone end of the reach rod, 11. The other end of the reach rod isconnected to the power reverse gear, 12. The lever is fulcrumed,intermediate itslength, on a pin, 10, which is attached to the quadrantsupport, 13. i

A latch handle, 14, is pivoted to the upper arm of the lever, by a pin,l l and to one end of a link, 16, by a pin, 16*. The other end of thelink is pivoted to the latch, 18, which is mounted for vertical movementin a housing, 19. The latch is formed with a vertical slot, 20, throughwhich passes a bolt, 21, and is provided. at its bottom, with a row ofteeth, 22, adapted to engage. in the notches,

23, of a quadrant, 24, bolted to the support, 18. The upper face of thequadrant is notched foronly a portion of its length, an

end portion being left smoothfor a purpose which will hereinafter beapparent.- V V -The latch is normally urged downward,

so that its teeth will engage the notches in with the latch down, atwhich point. the teeth of the latch will. drop into notches in thequadrant, locking the lever.

\Ve have observed that engineers, in starting locomotives, push thereverse lever to Late cut-off position, but frequently neglect to returnit toeerly cut-off position when the loco,

motive is running. Thisneglect is the source,-

forged with a lateralextension, 31, in which aihelical'spring, 32, is

is provideda cylindrical pocket. Qne end of fitted inthe pocket and theother end of the spring projects forwardly of the reverse lever, and isenclosed in. a cylindrical casing, 34, adapted to telescope intothepocket, when the spring is compressed. In order to secure the casing,34-, to the spring, and to provide for adjusting the spring to differentcompression lengths, a bolt, 35, is. employed. This bolt has a head,which fits in n recessin the end of-tlie casing, 34, undo shank,whichpassesthrough the end of the casing, and. the end of the. pocket.The endof the bolti projecting heyondthe endof the pocket, is threadedand carries two nuts, 36, by which any desired adjustment of the springmay heeifected.

Theoperation of the device is asfollows. In starting the locomotive, theengineer grasps the handles of the lever and the latch, and exerting asqueeze, frees the tcethof'the latch from the notches inthe quadrant,pen niitting the lever to be pushed to late cut-off position. As thelever is pushed to late cutoif' position, the cylindrical casing, 34,Will be brought into abutment With the stop, 27, whereupon the casing,34, will telescopeinto thepocket, compressingthe spring, 32, andpermitting the lever to he pushed'to late. cutoff position. After thelocomotivejisstarted the engineer releases the lever, whereupontlielatch drops, but as the end portion of the quadrant beneath the atohisunnotphed, the lever is free to homered-back to early cut-oil position,by the action of the spring, 32. When the lever reaches early. cut-off.position, the teeth of the latch engage notches in the quadrant, therebylocking the lever.

Qneof he obvious-m d fications of; the ventien, Which is a mechanicalequivalent of the form illustrated, is to apply the spring device .tothequadrant and the stop'to the lever.

-'Hhe presentfinvention pmvides a reverse lever. mechanism enabling thereverse lever to bepushed to, full: cut-off position to start. thelocomotive, but which will return the lever automatically to earlycut-elf; position, inrespective of raw bar pull, immediately that manualpressure on the lever is released, thus 7 ensuningi the propercutl-offofi the: valves. for

starting and nunningiconditions, andobuiating-anychanceofr'wnsteiofpsteam by reasoniof the negligence of: the engineer.Theimprovementi' effects a substantial economyin operating costs. i

It is to be noted that for aswitching engine, bothends of the quadrantshould be made unnotched, to permit the leverto bethrownto lateouteofiposition, for either ahead; or reverse, and'asuitable spring orsprings, and stopsprovided to effect the-automatic return of the leverto. early cut-oil position. from either end of the quadrant.

We claim asour invention and desire: to secure by Letters Patent: l

Distributingivalve operatingmechanisms,

comprising, in combination with the reach rod and the hand leveroperatively connected thereto, of al quadrant: over which saidgleverplays, notches in thecentre portion only of sai quadrant, alatch carriedby said lever to engagesaid notches, a-handle for lifting said latchout: of'suchengagement. a stop secured to one end of said'quadrant, asocket carried by said leverad'jacent the quadrangle hollow pistonslldablein said socket, a spring between the socket and piston ends, andmeans to limit the outward movement ofsaidpiston by saidspr-i-ng.

Annnnn W; BRUCE. JOSEPH B; ruins:

